US4819256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radiographic sensitivity for detection of flaws and cracks
Assignee: American Science and Engineering Inc
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Filing: 1987-04-20
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Granted: 1989-04-04
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Expires: 2007-04-20
Abstract
Abstract A method of imaging for enhancing detection of cracks or flaws in an object using penetrating radiation is disclosed wherein a contrast medium is applied to an object before illumination and scatter radiation is detected from the object. This is achieved by employing a flying spot scanner and a backscatter imaging technique allowing imaging of objects which are not completely accessible, e.g. imaging the object where only one side accessible.
Inventors
- 👤 Martin Annis
- 👤 Paul Bjorkholm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:25
CPC Classifications
G; G01; G01N; G01N23/00; G01N23/02; G01N23/06; G01N23/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
149 words
A method of imaging for enhancing detection of cracks or flaws in an object using penetrating radiant energy comprising the steps of: (a) providing a beam of penetrating radiant energy and repeatedly sweeping said beam over a line in space, supporting an object for illumination by said beam and providing relative motion between said object and said line in space, (c) providing a radiation detector responsive only to scattered energy from said object as a consequence of its illumination by said beam of penetrating radiant energy, (d) applying a contrast medium to said object prior to said illumination, said contrast medium selected as one with atomic number significantly different from an atomic number characterizing said object so as to provide contrast in a scatter image, and (e) using signals produced by said radiation detector to develop an image representing cracks or flaws within which said contrast medium has accumulated.
Claim 2
Independent Claim
149 words
A method of imaging for enhancing detection of cracks or flaws in an object using penetrating radiant energy comprising the steps of: (a) providing a beam of penetrating radiant energy and repeatedly sweeping said beam over a line in space, supporting an object for illumination by said beam and providing relative motion between said object and said line in space, (c) providing a radiation detector responsive only to scattered energy from said object as a consequence of its illumination by said beam of penetrating radiant energy, (d) applying a contrast medium to said object prior to said illumination, said contrast medium selected as one with atomic number significantly different from an atomic number characterizing said object so as to provide contrast in a scatter image, and (e) using signals produced by said radiation detector to develop an image representing cracks or flaws within which said contrast medium has accumulated.
Claim 3
Dependent Claim
29 words
The method of claim 1 in which said radiation detector provided in said step (c) has an active area large in relation to a cross section of said beam.
Claim 4
Dependent Claim
35 words
The method of claim 7 in which said step of applying a contrast medium includes contacting said object, by wiping, immersing or spraying with a liquid contrast medium, and removing excess amounts of said medium.
Claim 5
Dependent Claim
14 words
The method of claim 3 in which said contrast medium is an iodinated oil.
Claim 6
Dependent Claim
25 words
The method of claim 1 or 7 in which said step of applying a contrast medium includes exposing said object to a gaseous contrast medium.
Claim 7
Dependent Claim
12 words
The method of claim 5 in which said gaseous medium is xenon.
Claim 8
Dependent Claim
48 words
The method of claim 1 which comprises the further steps of: (f) providing a second radiation detector responsive to energy transmitted, unchanged in direction, through said object, and (g) using signals produced by said second radiation detector to develop a second image representing a shadowgraph of said object.
Claim 9
Dependent Claim
74 words
The method of claim 7 which comprises the further steps of: (h) providing a third radiation detector responsive substantially only to a predetermined fluorescence line from said contrast medium, (i) using signals produced by said third radiation detector to develop a third image representing a shadowgraph of said object, wherein (j) said step (a) includes selecting an energy level of said beam as sufficient to induce said predetermined fluorescence line from said contrast medium.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-03 | 1992-10-03 | 1993-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-03 | 1996-10-03 | 1997-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-03 | 2000-10-03 | 2001-04-04 | $7700.00 | Window Closed / Lapsed |